The response of power stations to autonomous 'grid friendly' devices.

The aim of this study was to examine whether so-called ``grid friendly'' devices can have undesirable effects on the power grid, and what design of grid friendly device is best suited to providing additional protection to the grid. This report first develops a simplified model for a power grid, looks at the conditions for stable operation of grid friendly devices, examines alternative designs, and makes recommendations for the design of grid friendly devices.